We propose to use our still developing computer methods for image analysis coupled with Golgi, Nissl, electron microscope and axon stains to study the effects of early environment on the development of dendrites, axon terminals, cell bodies and synapses in cortex. Visual cortex of cat will be used as a model. Correlative electrophysiological studies of receptive fields of single neurons will attempt to relate receptive field characteristics with dendrite morphology.